Thévenin’s Theorem

Question 1

Finding the current in any branch

Answer 1

• remove the resistance R from that branch
• determine the open-circuit voltage, E, across the break
• remove each source of EMF, to calculate r (add all Rs together)
• redraw circuit to Thévenin’s equivalent
• then workout the current, E = I(R + r)

Question 2

Power produced

Answer 2

• P = IV
• P = I^2R

Question 3

Maximum Power Transfer Theorem

Answer 3

Pmax = 1/4 v^2 / R

Pmax occurs when load resistance = internal resistance

*voltage (V)
*internal resistance (R)